Traffic Grooming Capabilities Research Articles

A machine learning assisted optical multistage interconnection network: Performance analysis and hardware demonstration

AbstractIntegration of the machine learning (ML) technique in all‐optical networks can enhance the effectiveness of resource utilization, quality of service assurances, and scalability in optical networks. All‐optical multistage interconnection networks (MINs) are implicitly designed to withstand the increasing high‐volume traffic demands at data centers. However, the contention resolution mechanism in MINs becomes a bottleneck in handling such data traffic. In this paper, a select list of ML algorithms replaces the traditional electronic signal processing methods used to resolve contention in MIN. The suitability of these algorithms in improving the performance of the entire network is assessed in terms of injection rate, average latency, and latency distribution. Our findings showed that the ML module is recommended for improving the performance of the network. The improved performance and traffic grooming capabilities of the module are also validated by using a hardware testbed.

QoT-aware elastic bandwidth allocation and spare capacity assignment in flexible island-based optical transport networks under shared risk link group constraints

This paper focuses on the problem of provisioning multi-granularity static lightpath connections with fault-tolerant requirements in survivable island-based translucent optical networks with traffic grooming capabilities. The problem is tackled for the first time, to the best of our knowledge, taking into account both Quality of Transmission (QoT) and Shared Risk Link Group (SRLG) constraints. A two phase heuristic algorithm is proposed relying on a novel generic purpose-built auxiliary graph model that may support various factors of network heterogeneity (i.e., network nodes with different wavelength-conversion, regeneration and traffic grooming capabilities), and represent numerous network constraints related mainly to QoT requirements and network-resources. The purpose of the proposed heuristic is to optimize the utilisation of the available network resources and hence the network throughput through the simultaneous use of traffic grooming and two resource sharing techniques namely the Generalized Backup-Backup multiplexing (GBBM) and the Generalized Adaptive Primary-Backup Multiplexing (GAPBM) which are combined for the first time, as far as we know, under a static traffic scenario, and performed in such a way that 100% QoT-aware SRLG-fault recoverability is still guaranteed for all serviced lightpath requests. The performances of the proposed solution are demonstrated through multiple simulation experiments conducted on different network topologies.

Energy-Aware Algorithms for IP Over WDM Optical Networks

To date, the main limitation to the development of telecom networks mainly depended on two factors, namely the cost of the network equipment and transmission. However, nowadays, the enormous spread and growth of the Internet has resulted in a significant increase in the energy consumption of the network equipment. Particularly, the rise in Internet traffic has led to both the increase of the amount of required equipment and the augmentation of energy consumption of such network devices. Consequently, CapEx and OpEx of modern telecommunication networks render the market penetration of such deployment laborious. This surge in power consumption may ultimately lead to an impediment to this continued growth. Since climate change and environmental protection are also of rising concern, many research efforts are being made to raise awareness of environmental issues and reduce the energy footprint of telecommunication networks. In this context, this study targets the reduction of the energy consumption of an IP over WDM backbone network. Already known lightpath bypass and traffic grooming strategies have been used. Although previously proposed schemes based on lightpath bypass approaches and traffic grooming capabilities have been implemented and consequently are able to reduce the overall power consumption of an optical core network, they do not bear in mind, first, the number of the established lightpaths in the virtual topology and second, the exploitation of the residual capacity of the existing lightpaths. This study overcomes the above drawbacks by introducing three novel heuristic schemes which manage to significantly lower the number of the established lightpaths in the virtual topology and take advantage of the remaining capacity of the optical paths by exploiting the lightpaths’ resources in a more efficient way. These power-aware heuristics will focus on energy efficiency issues related to the planning and the operation phase of a WDM optical network. Extensive simulation results indicate a promising performance improvement in terms of power consumption when these proposed heuristics are compared to similar, already developed, techniques for energy saving.

Sparse Traffic Grooming in Translucent Optical Networks

Traffic grooming is important in the design and operation of translucent optical networks. This paper investigates sub-wavelength traffic grooming in a translucent optical network and shows how to take advantage of sub-wavelength traffic grooming capability of sparsely distributed opaque switch nodes. An efficient heuristic, called the virtual nodal degree ranked algorithm, is employed to select the best locations for opaque switch nodes. New mixed-integer linear programming (MILP) optimization models are developed to optimally groom sub-wavelength traffic demand in the translucent optical network. The models maximize served sub-wavelength traffic demand under a limited network capacity and minimize required wavelength capacity subject to the condition that all the traffic demands are served. The models are novel in optimization methodology because they incorporate both the arc-node and the arc-path multi-commodity optimization techniques for a single problem. Based on simulation studies, it is found that the performance of sub-wavelength traffic grooming of a translucent network is substantially improved by increasing the number of opaque switch nodes. For some network topologies, the performance saturates as the number of opaque switch nodes increases, though the phenomenon is not general for any type of network topology.

Future Internet Infrastructure Based on the Transparent Integration of Access and Core Optical Transport Networks

It is increasingly recognized that the Internet is transforming into a platform providing services beyond today’s expectations. To successfully realize this transformation, the structural limitations of current networking architectures must be raised so that information transport infrastructure gracefully evolves to address transparent core–access integration, optical flow/packet transport, and end-to-end service delivery capability, overcoming the limitations of segmentation between access, metro, and core networks and domains. We propose and evaluate an integrated control plane for optical access and core networks, which addresses the above consideration. The proposed control plane can lead to a unified transport infrastructure integrating state-of- the-art components and technologies including wavelength division multiplexing, passive optical networking, and optical packet routers with inherent traffic grooming capabilities. The performance of the proposed architecture is assessed by means of simulation in terms of cost, resource utilization, and delay.

Adaptive algorithm for dynamic traffic grooming in WDM mesh networks

Aiming at the problem of dynamic traffic grooming in WDM mesh network,the paper presented an adaptive algorithm for dynamic traffic grooming based on layered auxiliary graph network model.According to different traffic requests and grooming capabilities in the current network state,the algorithm applied corresponding strategy of traffic grooming for allocating network resource exactly,in order to reduce average network block probability.The simulation results show that the network performance can be improved significantly by the proposed algorithm.

Multiple link failures survivability of optical networks with traffic grooming capability

This paper investigates the problem of survivable traffic grooming (STG) in shared mesh optical networks and proposes different frameworks for improving the survivability of low speed demands against multiple near simultaneous failures. Spare capacity reprovisioning has recently been considered for improving the overall network restorability in the event of dual failures; here, after the recovery form the first failure, some connections in the network may become unprotected and exposed to new failures. Capacity reprovisioning then allocates protection resources to unprotected and vulnerable connections so that the network can withstand a future failure. In this paper, we propose two different reprovisioning schemes (lightpath level reprovisioning, LLR, and connection level reprovisioning, CLR); they differ in the granularity at which protection resources are reprovisioned. Further, each of these schemes is suitable for a different survivable grooming policy. While LLR provides collective reprovisioning of connections at the lightpath level, CLR reprovisions spare bandwidth for lower speed connections instead. We use simulation methods to study the performance of these schemes under two grooming policies (PAL and PAC), and we show that while CLR reprovisions substantially many more connections than LLR (i.e., potentially more management overhead) CLR yields a much better network robustness to simultaneous failures due to its superior flexibility in using network resources.

Shared Sub-Path Protection Algorithm in Traffic-Grooming WDM Mesh Networks

In this paper, we investigate the problem of dynamically establishing dependable connections in wavelength division multiplexing (WDM) mesh networks with traffic-grooming capabilities. We first develop a new wavelength-plane graph (WPG) to represent the current state of the network. We then propose a dynamic shared sub-path protection (SSPP) scheme based on this WPG. To establish a dependable connection, SSPP first searches a primary path for each connection request, and then it segments the found path into several equal-length sub-paths, and computes their corresponding backup paths, respectively. If two sub-paths in SSPP are fiber-disjoint then their backup paths can share backup resources to obtain optimal spare capacity. Based on dynamic traffic with different load, the performance of SSPP has been investigated via simulations. The results show that SSPP can make the tradeoffs between resource utilization and restoration time.

Traffic grooming in an optical WDM mesh network

In wavelength-division multiplexing (WDM) optical networks, the bandwidth request of a traffic stream can be much lower than the capacity of a lightpath. Efficiently grooming low-speed connections onto high-capacity lightpaths will improve the network throughput and reduce the network cost. In WDM/SONET ring networks, it has been shown in the optical network literature that by carefully grooming the low-speed connection and using wavelength-division multiplexer (OADM) to perform the optical bypass at intermediate nodes, electronic ADMs can be saved and network cost will be reduced. In this study, we investigate the traffic-grooming problem in a WDM-based optical mesh topology network. Our objective is to improve the network throughput. We study the node architecture for a WDM mesh network with traffic-grooming capability. A mathematical formulation of the traffic-grooming problem is presented in this study and several fast heuristics are also proposed and evaluated.